The invention relates to a workpiece carrier device used for the processing of workpieces, especially in vacuum appliances, and in particular for coating said workpieces.
Published International Patent Application WO 2007/025 397 A1 discloses a workpiece carrier device of the generic type, in which the transmission part is realized as a driving disc which is eccentrically joined to a rotational axle which is closely surrounded by a corresponding recess on the transmission part. It is possible to influence the transmission ratio between the rotation of the workpieces and that of the rotary frame only via an auxiliary gear set which directly controls the motion of the driving disc.
A further workpiece carrier device is known from EP 1 153 155 A1. In this case, the workpiece holders rotatably mounted on rotary frames are rotated in that in each case a toothed wheel on the workpiece holder engages with a ring gear which coaxially surrounds the drive axis of the rotary frame and is torsionally rigid in relation to the base frame. This known workpiece carrier device is of a relatively complex structure. The transmission ratio is selectable only within fairly narrow limits.
In the case of one of the workpiece carrier devices disclosed by DE 198 03 278 A1, the rotation of the workpiece holders is effected by drivers which are anchored to the base frame and engage temporarily with said workpiece holders. In this case, the rotation is intermittent, which is usually disadvantageous per se and can impair the quality of the workpieces, especially when a coating consisting of a plurality of very thin layers is being applied.
DE 103 08 471 A1 discloses a workpiece carrier device in which workpiece carriers are disposed on a rotary frame in a plurality of concentric rings. Each workpiece carrier of a ring is made to rotate by an intermediate gear set engaging with a stationary central wheel on the rotary frame. The workpiece carriers pertaining to a ring are operatively connected to one another in such a way that this rotation is transmitted to the remaining workpiece carriers.